Ralph Lauren France 5 - ethyl-2 ,4 - dihydro - 4 - (2 - phenoxyethyl)-3H-1, Nike Free Run, 2,4 - triazole-3 - one synthetic overall yield of 53%. Keywords: 2-thiophene acetic acid; the cephalosporin class of antimicrobial agents; intermediates; synthesis of CLC number: 0626.12 Document code: A Article ID: 1001-8255 (2004) 04.0201-02 2-thiophene acetic acid (1) is a broad-spectrum antibiotic intermediate for Cefalotin (cefalotin), Cephaloridine (cefaloridine), and cefoxitin (cefoxitin). The main synthesis routes are: (1) Thiophene acetylation to 2-acetylthiophene, followed by Willgerodt reaction with ethanol, sulfur powder, ammonia under high pressure to generate 2-thiophene acetamide, and finally hydrolysis, yielding only 20.9% [-]; (2) 2-(Chloromethyl) thiophene (2) and carbon monoxide, methanol, potassium hydroxide, pressurized drilling salt catalytic generation. Thiophene acetate, then hydrolyzed; (3) 2-thiophenecarboxaldehyde and 0c.◇ 201 • (IV-methyl-phenylamino) acetonitrile in the presence of potassium hydride generates cyano enamine, then 10% HCl hydrolysis method 2,3 reagents used are easy to get but expensive; (4) Acetyl thiophene with boron trifluoride ether complex and lead acetate oxidation rearrangement generates carboxylic acid ester, then hydrolyzed [the Act should not expand preparation. This article first obtains thiophene through chloromethylation reaction, without separation and purification, direct cyanation of 2-thiophene thiophene acetonitrile (3), then hydrolyzed [] 1 (Figure 1), the total yield is 53%, content of 99.7%. Synthetic routes experimental part of the l1-1) NaOH ◇ Figure XRC-1 micro melting point analyzer (Sichuan disciplines Instrument Factory), AvanceDMXS00 NMR spectrometer (Bruker Co., Switzerland), FTIRNexus470 infrared spectrometer (Nicolet), 1102 Gas Chromatograph Received Date: 2oo3 a O1.28 Author: Guohai Chang (1976), male, graduate, professional direction: the development of thiophene compounds. Tel: 0571-8795l620 E-mail: hc.g, @ 163.tom Added thiophene (126g, 1.5mol) and concentrated hydrochloric acid (129ml, 1.5mol) in a 500ml flask, at 5t0°C under stirring, dropping 37% formaldehyde solution (121.6g, 1.5mol) in 40min, simultaneously passing hydrogen chloride, Ralph Lauren Pas Cher, maintaining saturation. After 3h reaction (continued passage of hydrogen chloride), transferred to cold water (18Ora1), organic phase washed with cold water (150m1), light yellow containing reaction solution (150ml, l83g). In another flask, sodium cyanide (72g) added...
Synthesis of 5-Ethyl-2,4-dihydro-4-(2-phenoxyethyl)-3H-1,2,4-triazol-3-one ZHANG Xiao-Bo, JIANG Yong-Xiang (Dept. of Chemistry, Zhejiang University, Hangzhou 310027) ABSTRACT: 5-Ethyl-2,4-dihydro-4-(phenoxyethyl)-3H-1,2,4-triazol-3-one, an intermediate of antidepressant nefazodone, was synthesized from propionic acid hydrazide by condensation and cyclization to give 5-ethyl-1,3,4-oxadiazol-2(3H)-one which reacted with 2-phenoxyethylamine followed by cyclization with an overall yield of 66-3%. Keywords: 5-ethyl-2,4-dihydro-4-(2-phenoxyethyl)-3H-1,2,4-triazole-3-one; nefazodone; intermediate; synthesis
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